Speakers hissing when sound is down
 

So i just hooked up my Skylon Defcon IV's to an ARC KS300.2 and when i have the volume all the way down without the boat running you can hear a hissing sounds (that white sound like nothing is playing) is there a fix for this? I am running those at 2 Ohms, High pass set on 100 Hz, not running at full amp capacity yet (probably only turned up 250 RMS Not 350 RMS).

Are you running a WS420? I was getting more hiss when I ran one. You were able to reduce it a bit by turning down the MIC knob on the WS420. If you are not running one then nevermind, but thought I would throw that out there.

iam running Skylon Defcon IV's. I guess that many watts per speaker is just alot. They can handle a ton.

The gain has nothing to do with how much wattage you are putting to you speakers.

You probably need to tune it properly.

1.) set head unit or source at 75% of max volume.
2.) set amp to HP and start at 100hz
3.) turn gain level all the way and work it up slowly until you hear the speakers begin to slightly distort - turn it back a hair from that point.

You can adjust your crossover to tailor how you want it to sound.

Educate yourself on the topic: http://www.bcae1.com/gaincon2.htm

The only reason i have the speakers set at HP 100Hz is because the designer said thats what works best for these speakers. I think my problem lies in the head unit bing turned up 90% ill turn it down and see if that fixes it.

Make sure that your headunit and amp are grounded to the same place. i.e. both ran to the same battery and this will usually fix the problem.

Michael

You say you don't have the amp turned up to full capacity, that you only have it at about 250 WRMS, not 350RMS. How do you know?


My hunch is that what you are describing is your gain control, which has nothing to do with the amp capacity, but rather its sensitivity. By your comments, I bet you have your gain control at 3 or 4-o'clock..... That is way too high for 99% of all radios out there..... The hiss is coming from the gain stage of the amp....

A gain control is not a volume control, it is a sensitivity matching control. You want it as LOW as possible in order to get the greatest range of control from your radio's volume control. Ideally, you want the amp to just barely start clipping at about the same time your head unit starts clipping. This is an ideal setting, and it is usiually achieved with the gain control set in the left half of its control range, when viewed as a clock. IF you have youre gain set way above 12-o'clock, you are probably runnig out of amp power at the radio's half-volume point or less.

Murphy is right, you need to go to his link and read up on gain setting, and you can search this forum for several tutorials from myself, Tim at Wetsounds, and others. From that you should get a better understanding of what the gain knob is for and how to set it.

In the meantime, based on what you are telling us, turn yor gain control down from that 3 or 4-o'clock position and put it at 8 or 9-o'clock and watch the hiss go away. I could go ahead and write the whole gain setting tutorial but it is here several times; a good forum search will find it for ya.

Good luck, and for sure know this is supposed to be fun, so stick with it and post up any further questions after you have done some reading and after you have taken a look at turning the gains down! :)

Let us know-


Phil
Kicker

A breakdown of the entire system configuration would help, plus make, model, and year of your boat.

Phil put it very well in his post above. If you were running the head unit at 90%, then that is a major contributor to the noise.

Let me read up on the gain control situation since I miss understood what it ment, try to fix the situation and i will get back to you guys about my progress.Thank you so much for all your help, i really appreciate it.

After i went through the manual, I just relized that i was being an idiot. I was turning the gain nob and not the bass boost nob. But id like to more fully understand the gain, but that whould make sense.

You're not gonna want the bass boost turned up at all.

Hate is right. Bass boost should be totally off for your tower speaker application. Understand the bass boost is usually turing up a single band of EQ somewhere down around 40 Hz. You are setting the crossover to its hi-pass setting to limit low frequencies, where the bass boost control works. Turning bass boost up with hi-pass on is oxymoronic, sort of. It is counter-intuitive for sure... :D Doing so is turing the bass up at the same time you are trying to limit the bass with the crossover.

Crossover set to hi-pass. Crossover frequency set to somewhere between 80 and 120 or so, (your 100 Hz recommendation is real close).
Again, gain will need to be set by following one of the gain setting tutorials found in this forum or elsewehere.

VERY simply and quickly, (without talking to lots of other factors) turn your head unit to 75% or so. This is where most head units start crapping out. With a STORE BOUGHT CD, (not a questionable MP3 CD, or a file played from the headphone output of your iPod) play your stereo. Nickleback is a good example of a highly compressed, waveform dense group whose recordings work well for this, (it doesn't matter if you like them, it matters what the track does to the system... :D ). Start with the tower speaker amp gain turned all the way down, and turn it slowly up until the sound starts getting crunchy. Hopefully you can hear the crunchiness.... When the amp goes crunchy, it is beginning to distort as its output waveform is at the rail voltage maximum. From there, back the gain down a little until the sound is clean again. Set this way, your head unit craps out at the same time your amp does, and it gets you the best range of volume control AND the quietest gain setting for max amp power output.

Look at your gain control after doing this. IF it is past 12-o'clock you need to seriously question if you got the right CD to use, or you might want to question whether or not you can distinguish distortion from clean sound, (alas, many these days cannot!).

This quick gain setting tutorial is for a single tower amp only, and speaks nothing to tuning the rest of the system so understand that is a much larger more detailed set of instrucitons you will find elsewhere...

Hope that helps!

Phil
Kicker

Ok so here is what happened, I went and truned my head unit to 75% and brought my gain nob down to the 8 o'clock position (minimum) then worked it up till I heard the crackling. so heres were my problem lies. i found the right tone but there is still the White Noise sounds when the EQ volume is turned down. So I went back and backed the gain back down again and the noise went away, but the speakers arnt hardly on. should i be turning the volume down at the EQ or head unit? would that even make a difference?

So you have an EQ? And the plot thickens.....

What is the EQ volume turned to? neither source should be over 85% at anytime. I don't think my 420 ever gets passed about 75% and my head unit is < 80%
I use the EQ to control the volume.

Did you adjust the gain from factory on your 420? It usually comes at about half gain which is where it most commonly opperates best but it may need adjusting too.

Oh yeah reading back over that Diggs asked him if he had a 420 but he never answered.

ok no wetsounds 420, its a clarion. honestly id like to gut the whole stereo and start over but I am saving for a house so that wont happen anytime soon. So i turned the Head unit to 75% then the EQ to 75%. then mest with the gain. The real question is is there anyone of you that live in disco?

I have my H/U at 80% and gains dialed in on amps (didnt mess with WS420, left it at factory setting per Tim's advice). I do get hissing on the bullets (tower) when listening to only the in-boats. I didnt think there was anything that could be done about this. It isnt execessive, so doesnt bother me much. But if it were possible to illiminate, that would be cool.

yeah thats the thing, its not a huge deal but eliminating the white noise would be nice. I have found that my polks do it too, but since these speakers are so large they are louder.

This presents an interesting Q for the tuning gurus -- I personally set my gains with the volume on the source unit and the eq much higher than 75% (more like 90% on the HU and 100% on the EQ). My rationale is that I've made the system foolproof in that someone could crank both knobs all the way up I wouldn't be significantly overdriving the amps (potential to overdrive being 10% based on setting with HU at 90%). In contrast hatepain's method leaves a newbie with the ability to overdrive by approximately 45% (25% from HU + 25% of HU's 75% on EQ).

**EDIT -- NOTE that the latest version of the ws420 does not have adjustable gains. They are fixed at 5v.

Is there a right / wrong / preferred method? I've got a ws420 and I don't have hiss using my method (which results in the gains on the amps being lower if you think about it), but maybe this is why I was never able to get the hiss to go away when I added a waves maxxbass 103 to the signal chain?

Your last sentence is confusing, do you have hiss or not? I agree with your tuning method and don't like that "dont turn it up past this volume" game people have to play with their systems. Setting the source unit to 85% and tuning the amps properly should lead to minimal if any clipping when turned up all the way. None of which should or would damage equipment when the source unit is and will be turned up to 100% by someone at sometime. I've never had an issue on any system I've ever done this way.

I set the amplifiers with the source unit just below its clippiing threshold which could be 75 percent on some and 90 percent on others. You're trying to maintain the lowest noise floor yet you have to leave a little room for differing outboard sources or source material that has less inherent gain so that you don't cap the dynamics.
If the EQ isn't clipping with its master control at 100 percent then I would go the route of full gain. You want as much gain at the source end as possible..within limits.
The idea is to follow a set prescription for tuning rather than just a number. I would take a similar approach to crossovers, especially since the nomenclature on the side of some amplifiers can be as much as a full octave off.
shawndoggy, I really like the warmth that the Maxxbass brings to the lower midrange and midbass, particularly on tower speakers. But it does have a bit if ambient noise that is audible at low or no volume.

David
Earmark Marine

oh, I tried the maxxbass then pulled it because I couldn't get the low grade hummmmmmm to go away. Which was really disappointing because at volume the sound was much richer in the boat. As soon as the maxxbass was eliminated from the signal path the hum went away.

EDIT -- David, yeah, it is really a night and day difference with the Maxxbass, especially in the boat. Much much warmer. But I knew that the noise would drive me nuts, especially the first time that my wife asked "what's that noise?"

I've got a good story about a hiss. We had a brand new 2011 boat in this week (Boat Brand not to be mentioned). The boat had a factory installed system consisting of a 4 channel low power Clarion amp, 1 pair of titan 6x9 tower speakers and a 10 " sub running off it and the interior speakers running off the deck. Customer was complaining about a hissing noise straight out of the dealership. He wanted to remove the stock amp and, install 2 new Exile amps and an EQ. He requested a complete rewire of the system as well. He asked that if the noise persisted after we were complete that we spend a couple hours on debug..

Well system was complete and the hiss was still there (as we expected it would be) After a few hours of debug we traced the noise down to the gauge cluster. Noise sniffer took us to the general area around the gauges, when we would get our ears near the rear opening behind the gauges we could hear a clear wine coming from the gauge cluster, not doubt about it. This was hear with the radio off.

Moral of the story even a properly tuned system with all brand new gear can have a hiss that has nothing to do with the equipment, installation or the tuning, or even whether stainless steel screws were used or not.. ; )

Johnny,
What was the actual cause of the noise?

I don't have any of my equipment ever pushed to the 100% range even if I'm using an iPod. My theory is that it all can lead to distortion of the music starting from the source, onto the head unit, EQ then on to the amp. I certainly could be wrong though :) It just seems that if you keep it around that 75-85% of max range it still sounds good. If any one of them is cranked to 100% I'd be fine but if they all are I'm sure there'd be a problem.

Hey Johnny where'd ya get one of them fancy Noise Sniffers at? Looks like David has his notepad out to take notes as well.

@ Dave - Since it is a brand new boat - no hours, I stopped there, contacted the owner and let him know. Also called the dealer he bought it at and talked through it with the Service Manager and the Salesmen that sold them the boat. They where already aware of it and where glad to have it pin pointed to a general location. Whether the noise was generated at the gauges or somewhere closer to the ECU, Alternator .... I don't know, and we did not have the band width to dig much deeper looking for a problem that is covered under warrantee.

BTW picked up the sniffer off the neighborhood tool truck....

This sniffer found noise radiating from the steering rack in a Malibu last year. grounded the column and all gone. How would have even thought to look there.

Also works wonders when your working with AC and DC current in the same area. AC converters will generate some nasty noise and quickly introduce it into DC current in the local vicinity.

Johnny,
Noise sniffers we've got and we have dealt with our share of factory and phantom noises. Some of which were monsters to track down when it was an inherent flaw in the boat. I'm dying to know the actual cause of the noise in your boat so we don't have to waste the hour or two tracing it down. If you get a chance to talk to the dealer's service people and get an explanation, please share it. Experience is a good teacher but I'd rather learn the shortcut in this case.

David
Earmark Marine

I'll re hash this thread once I hear back from the dealer, but this could take a while. I expect the usual, blame it on the stereo guy, then take it back in the end once he has proven beyond a reasonable doubt that the stereo is not the cause.

I've been down that road one too many times with dealers, even the manufactures. We went rounds with Sanger for months over Jason's (BlackOps) V215 over what they thought was a voltage drop due to the "Stereo Install" In the end it was an issue with the wiring harness from the ECU to the controls that was causing the problem.